PHP

A little while back I needed to split a large Apache log file (3.5GB) up into smaller pieces and wanted to break it up into several files, with one for each day of the month. I initially tried using "grep" on the command line but this proved to be too slow, and I needed to run it once for each day and month so it was going to take 92 times to run, extracting just one day at a time over the course of three months. I ended up writing a quick little PHP script which was able to split the 3.5GB file into 92 files, one for each day of each month in under 4 minutes.

When compiling PHP with Sablotron there are errors which prevent PHP from compiling. This article covers what you need to do to enable PHP to compile correctly with Sabloton.

If you get the following error message in PHP then it means you need to have the PHP GD extension installed. Obviously the /path/to/file.php will be the actual path and filename of the PHP script the error occured in, and the line number will be the actual line.

Fatal error: Call to undefined function ImageCreateFromPNG() 
  in /path/to/file.php on line 379

You’ll also get this error message using other functions such as ImageCreateFromJPEG() if the PHP GD library is not installed.

This article covers howto fork a child process using the PHP command line client and PHP process control functions. Several examples illustrate how to create child processes and make the parent wait until they have finished before continuing processing.

APC is the Alternative PHP Cache, which is a free, open, and robust framework for caching and optimizing PHP intermediate code. What this means is that APC reads your PHP files, parses them into a more efficient binary format and then caches them in memory so that each request for your PHP files and PHP library files can be fed from the parsed cache. This will generally lead to a speed increase when serving a PHP site, especially one with a lot of library files. This post looks at how to install APC for PHP on Linux. The Linux distribution I used was CentOS 5, but it should be fairly similar for most distros.

"echo" and "print" are used in PHP for writing strings out to a stream. I have always used concatenation when writing out multiple strings with echo or print, but recently discovered that echo accepts multiple arguments or parameters, comma separated like a regular function call. This post does some benchmarking to see which is faster: echo with commas, echo with concatenation, or print with concatenation.